Their task was to act as part of the radar defenses of the United States in the Cold War, serving until 1965.

They would spend 30–45 days at sea regardless of weather, alternating with 15 days in port, monitoring aircraft approaching the United States in the Contiguous Radar Coverage System, an adjunct to the Distant Early Warning line under the Continental Air Defense Command.

The AGRs were augmented by twelve radar picket destroyer escorts (DERs) of the Edsall and John C. Butler classes, Lockheed EC-121 / WV-2 Warning Star aircraft, and in the Atlantic, Goodyear ZPG-2W and ZPG-3W blimps and Texas Towers.

[citation needed] The Guardian class spent more time at sea than any other U.S. Navy vessels, apart from ballistic missile submarines, averaging 220–250 days per year on patrol.

To make this very high amount of sea time as comfortable as possible for the crew, all sleeping quarters were air conditioned, each officer had a private stateroom, petty officers shared two-man cabins and enlisted men slept in four-man cabins (most other USN enlisted men at the time slept in hammocks, and in large berthing compartments regardless of type of bed).